Hexamethylene diisocyanate

Synonyms

1,6-Diisocyanatohexane; 1,6-Hexamethylene diisocyanate; 1,6-Hexanediol diisocyanate; 1,6-Hexylene diisocyanate; HDI; HMDI; Hexamethylendiisokyanat [Czech]; Hexamethylene-1,6-diisocyanate; Hexane 1,6-diisocyanate; Hexane, 1,6-diisocyanato-; Isocyanic acid, diester with 1,6-hexanediol; Metyleno-bis-fenyloizocyjanian [Polish]; Szesciometylenodwuizocyjanian [Polish]; TL 78; [ChemIDplus]

Category

Diisocyanates

Description

Clear, colorless to slightly yellow liquid with a sharp, pungent odor; [NIOSH]

Sources/Uses

Used as a cross-linking agent to manufacture dental materials, contact lenses, medical adsorbents, and polyurethanes; may be released during the spraying of polyurethane paints; Commonly used as a hardener in polyurethane automobile paints; [HSDB] Occupational asthma reported in a spray painter; [Malo] Used to make polyisocyanate products for curing agents in polyurethane paint systems (automobile, marine, industrial maintenance, and other high-performance coatings); [ACGIH]

Comments

"Isocyanate HP," a form of hypersensitivity pneumonitis, has been reported. [Rosenstock, p. 346] May cause skin sensitization; [ICSC] "1,6-Hexamethylene diisocyanate (HDI) is either conjugated or hydrolyzed to the corresponding 1,6-hexamethylene diamine (HAD), which may then be conjugated to proteins, macromolecules, or acetyl groups, following absorption. . . . The recommended BEI of 15 ug HAD/g creatinine is based on the level of HAD expected with an exposure to the equivalent of the TLV-TWA of 0.005 ppm (0.034 mg/m3). The TLV-TWA is intended to protect workers from potential eye, nose, and upper respiratory tract irritation and respiratory sensitization." [ACGIH] See "DIISOCYANATES."

Reference Link #1

Biomedical References

1,6-Hexamethylene diamine in urine (with hydrolysis) = 15 ug/g creatinine at end of shift; [TLVs and BEIs]

Insufficient data

0.005 ppm

0.005 ppm

0.5 mm Hg

LCLo (rat) = 60 mg/m3/4h

Reference Link #2

Yes

Yes

Yes

Diseases

Occupational diseases associated with exposure to this agent:

• Asthma, occupational
• Contact dermatitis, allergic
• Isocyanate HP

Processes

Industrial Processes with risk of exposure:

• Painting (Pigments, Binders, and Biocides)
• Plastic Composites Manufacturing